Generally, in electrical circuits having multiple interconnected functional elements, such as integrated circuits (ICs), printed circuit boards (PCBs), and the like, it is beneficial to have timing synchronization between signals applied to the various functional elements. For example, timing synchronization enables events between parallel transmitting functional elements (e.g., transmitters) and parallel receiving functional elements (e.g., receivers) to be synchronized. Timing synchronization may be achieved by equalizing propagation delays in signal path lengths of interconnects between the functional elements.
However, physical separation between functional elements varies, e.g., due to layout constraints, physical size limitations, and the like. Therefore, it is often the case that the interconnects between the functional elements have different lengths. The variations in the lengths result in timing skew between the interconnects, e.g., due to longer signal propagation times in longer interconnects, thus preventing timing synchronization. In addition, the variations in the lengths can result in mismatch across the interconnects, which can reduce overall performance of the electrical circuit or the system incorporating the electrical circuit.
One conventional approach to equalizing propagation times is to keep certain properties of the interconnects (e.g., characteristic impedance Zo and/or propagation constant γ) uniform, while adjusting the lengths of the interconnects, so that all the signal path lengths are equal. However, layout constraints, physical size limitations and the like, may prevent the necessary variations in interconnect lengths. Another conventional approach is to vary the characteristics of the transmitting and/or receiving functional elements themselves, depending on corresponding transmission distances and wire lengths. However, in order to implement this approach, multiple functional elements must be designed, which is time consuming, expensive and inefficient. Another conventional approach is to use passive devices to control the transmitted signal characteristics. However, this requires adding additional components to the circuit, such as a source terminated resistor or a matching network, which may impact cost and contribute to signal loss and other inefficiencies.